Analyses of plant responses to boron deprivation

硼是植物必需的微量营养素。缺硼是全球农作物生产的主要制约因素之一。然而，目前尚不清楚缺硼是如何导致各种代谢紊乱和细胞死亡的。为了了解这一机制，我们分析了缺硼诱导的拟南芥植株的生理变化。根伸长区的细胞在缺硼后1h内大量积累活性氧并死亡。缺钙时也可观察到类似的反应。分析表明，这种即时反应是由于细胞壁中新合成的果胶多糖未能交联而引发的。

Boron is an essential micronutrient for plants. Boron deficiency is one of the major constraints in crop production worldwide. However, it remains unclear how boron deficiency causes various metabolic disorders and cell death. To understand the mechanism, we analyzed the physiological changes in Arabidopsis plants induced upon boron deprivation. The cells in root elongation zone overaccumulated reactive oxygen species and died within 1 h after boron deprivation. Similar responses could be observed under calcium deprivation. Analyses suggested that the immediate responses were triggered by a failure in cross-linking the cell wall pectic polysaccharides which were newly synthesized in elongating cells.